System and method for performing calculations using a portable electronic device

ABSTRACT

An apparatus and method for performing calculations is provided so that a paradigm of a tape is utilized in a calculator application that executes on a computing platform and which is configured to enable a user to see and interact with multiple virtual tapes that each show numerical values and operators. Each tape functions as a user-accessible memory and a memory value may be recalled from any one tape and that value placed on any other tape. The calculator application is configured to enable the user to enter a sequence of values and operators which are all displayable on a given tape, as well as support the user&#39;s ability to edit any value or operator that was previously entered on that tape. Calculations are updated to reflect the user&#39;s edits on both the tape currently being edited and any other tape that uses the edited tape as a memory.

BACKGROUND

Portable electronic devices such as calculators and multipurposecomputing platforms that can run software applications that providecalculator functionalities typically display information line by line(i.e., one line at a time). Such information may include numericalvalues that a calculator user enters using a user interface such as akeypad which includes number keys (i.e., buttons) as well as keys formathematical binary operators and unary functions. Many calculatorsinterpret keystrokes using an immediate execution mode. For binaryoperations (e.g., addition, subtraction, multiplication, division) inimmediate execution mode, intermediate results are calculated as eachkey is pressed for each operation. The order of operations inmathematical expression is not taken into account by immediate executionmode calculators unless brackets or parentheses are supported by thecalculator and utilized by the user. For unary operations (e.g., squareroot, reciprocal, exponents, etc.), the user keys the numerical value infirst, followed by the unary operator. The immediate execution mode ofoperation compares with that utilized in formula-based calculators wherethe user types in an entire expression and then presses an “enter” keyto evaluate the expression.

Most users find immediate execution mode calculators to bestraightforward enough to use, particularly for short and simplecalculations. However, even for simple calculations, mistakes can easilybe made and be difficult to spot. Errors can occur using many currentcalculators for a variety of reasons and commonly result because ofkeystroke errors and/or use of an incorrect sequence of button pushesthat misapplies precedence rules when performing calculations ofexpressions in which the order of operations affects the results. Theinability to see prior entries before the current line and the fact thatoperators are not typically shown on the calculator's line-by-linedisplay can compound difficulties because the user cannot see that anerror was made or where in a given calculation it was made. Manycalculators support use of a memory feature to help improve calculatorfunctionality (and help address, for example some of the aforementionedissues in operation precedence) by enabling users to store a result of acalculation and then recall the result in a subsequent calculation.However, the number of available memories is typically limited in manyconsumer-oriented calculators to just one or two. In addition, thecalculations used to create the stored results can still be prone to theerrors that result from the limitations of the line-by-line display.

This Background is provided to introduce a brief context for the Summaryand Detailed Description that follow. This Background is not intended tobe an aid in determining the scope of the claimed subject matter nor beviewed as limiting the claimed subject matter to implementations thatsolve any or all of the disadvantages or problems presented above.

SUMMARY

An apparatus and method for performing calculations is provided so thata paradigm of a tape, like that employed by a traditional adding machineor printing calculator, is utilized in a calculator application thatexecutes on a computing platform and which is configured to enable auser to see and interact with multiple virtual tapes that each shownumerical values and operators using a scrollable user interface window.Each tape functions as a user-accessible memory and a user may recall amemory value (which is typically the last value on the tape) from anyone tape and place that value on any other tape, for example, as part ofa calculation. The calculator application is configured to enable theuser to enter a sequence of values and operators which are alldisplayable on a given tape, as well as support the user's ability toedit any value or operator that was previously entered on that tape. Thecalculator application will update the calculations to reflect theuser's edit on both the tape currently being edited and any other tapethat uses the edited tape as a memory.

In various illustrative examples, the calculator application is embodiedsubstantially using software that executes on a portable electronicdevice such as a smartphone or personal media player. The calculatorapplication enables the user to name tapes as well as provide textualcomments and line-annotations on the tapes. A memories window issupported by the calculator application's user interface so that theuser can see a summary of tape names and memory values before recallinga value. Multiple different calculations may be included on a tape andcalculations using various units of time (e.g., hours, minutes, seconds,days, months, years) are supported by the calculator application. Thecalculator application is also configured with functionality to e-mailtapes selected by the user to specified recipients.

Advantageously, the calculator application provides enhanced featuresand functionalities, compared to ordinary conventional calculators, thatcan typically be expected to increase productivity, improve the qualityof the user experience when performing calculations, and reduce theoccurrence of errors. In particular, the ability to see an entire chainof calculations, including all values and operators, and edit the valuesand operators to make desired changes facilitates much more user controlover calculations and provides a visual confirmation of values andoperators so that longer or more complex calculations can be performedwith a high degree of confidence in the calculated result. In addition,the calculator application's support for multiple tapes, each of whichfunctions as a memory to the other tapes provides additional flexibilitywhen performing calculations. The textual commenting and annotationfeatures provide the user with more options to organize and trackcalculations.

This Summary is provided to introduce a selection of concepts in asimplified form that are further described below in the DetailedDescription. This Summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tobe used as an aid in determining the scope of the claimed subjectmatter.

DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts an illustrative portable computing environment in which auser interacts with an electronic device that supports a touchscreen;

FIG. 2 shows an alternative landscape orientation for an electronicdevice that displays a virtual keyboard on the touchscreen;

FIG. 3 shows an illustrative example of an electronic device thatutilizes physical controls;

FIG. 4 depicts an illustrative example of an electronic device that usesa flip, or clamshell form factor;

FIG. 5 depicts an illustrative touchscreen that supports userinteraction through icons;

FIG. 6 depicts an illustrative software architecture that may besupported on an electronic device;

FIG. 7 is a schematic view of functional components in an illustrativeelectronic device;

FIG. 8 depicts an illustrative arrangement in which an electronic deviceis coupled to external computing platforms and service/contentproviders;

FIG. 9 depicts a user launching the calculator application on anelectronic device;

FIG. 10 depicts an illustrative user interface that may be provided bythe calculator application including a main calculator window;

FIG. 11 depicts an illustrative function panel window that may beprovided by the calculator application;

FIG. 12 depicts an illustrative preferences window that may be providedby the calculator application;

FIGS. 13 and 14 depict an illustrative decimal precision window that maybe provided by the calculator application;

FIG. 15 illustrates how the calculator application supports the use of avirtual tape;

FIGS. 16 and 17 illustrate how a user may scroll through a tape that isdisplayed in a display area of a main calculator window;

FIG. 18 illustrates how multiple virtual tapes may be supportedsimultaneously as respective memories that may be accessed by thecalculator application;

FIG. 19 depicts an illustrative memories window that shows a set ofillustrative tapes which are accessible as memories;

FIG. 20 depicts how a particular tape may be accessed for display fromthe memories window;

FIGS. 21-24 depict illustrative calculations that are stored in varioustapes;

FIG. 25 depicts how details about a particular tape may be accessed fromthe memories window that may be provided by the calculator application;

FIG. 26 depicts an illustrative memory details window for anillustrative tape that contains calculations pertaining to householdexpenses;

FIG. 27 depicts an illustrative keyboard that is displayed with which auser may enter a name for a tape as well as comments and/or annotations;

FIG. 28 depicts a tape named “Household Expenses” that includes acomment;

FIG. 29 depicts a tape named “Household Expenses” that includes acomment and annotations;

FIG. 30 shows an illustrative e-mail window that may be provided by thecalculator application;

FIG. 31 depicts how a memory value (e.g., the last value on a tape) maybe recalled using the memories window that may be provided by thecalculator application;

FIG. 32 depicts a tape prior to a recalled value being displayed;

FIG. 33 depicts a tape after a recalled value is displayed;

FIGS. 34 and 35 show how a value on a tape may be edited;

FIG. 36 depicts an illustrative tape which shows how an edited value isreflected in subsequent calculations on a given tape and how an editedvalue is reflected in another tape that relies on the given tape as amemory;

FIG. 37 depicts an illustrative tape which shows that operators may beedited;

FIG. 38 depicts an illustrative tape which shows how time values may beused for calculations and how time units for a given value can beconverted on the tape;

FIG. 39 depicts an illustrative tape which shows how different time unitpreferences can affect a calculation and how multiple calculations maybe shown on a given tape;

FIG. 40 depicts an illustrative tape which shows how parentheses areindented to show the level of embedding within a calculation;

FIG. 41 depicts an illustrative display window that may be displayed aspart of the user interface of the calculator application;

FIGS. 42-44 show how a user may touch the display window and drag tochange the decimal precision of the displayed value; and

FIGS. 45 and 46 show how a value in the display window may be convertedto different units by tapping the unit indicators.

Like reference numerals indicate like elements in the drawings. Elementsare not drawn to scale unless otherwise indicated.

DETAILED DESCRIPTION

FIG. 1 shows an illustrative computing environment 100 in which a user102 interacts with an electronic device 105 which supports the presentcalculator application using a touchscreen 110 that is integrated intothe device. Device 105, as shown in FIG. 1, may typically be configuredas a portable electronic device or information appliance such as amobile phone, smart phone, PDA (personal digital assistant),ultra-mobile PC (personal computer), tablet PC, handheld game device,digital media player, digital camera, and the like. For example, theelectronic device 105 could be a digital media player such as the iPod™made available by Apple Computer or a personal e-mail appliance such asthe Blackberry™ made available by Research in Motion. Devices includingtelephony capabilities such as Apple Computer's iPhone™ may also beutilized to support the present calculator application. Largerform-factor devices such as Apple Computer's iPad™ are also contemplatedas being suitable platforms in some implementations of the calculatorapplication.

Typically, the touchscreen 110 is made up of a touch-sensor componentthat is constructed over a display component. The display componentdisplays images in a manner similar to that of a typical monitor on a PCor laptop computer. In many applications, the device 105 will use aliquid crystal display (“LCD”) due to its light weight, thinness, andlow cost. However, in alternative applications, other conventionaldisplay technologies may be utilized including, for example, cathode raytubes (“CRTs”), plasma-screens, and electro-luminescent screens.

The touch sensor component sits on top of the display component. Thetouch sensor is transparent so that the display can be seen through it.Many different types of touch sensor technologies are known and may beapplied as required to meet the needs of a particular implementation.These include resistive, capacitive, near field, optical imaging, straingauge, dispersive signal, acoustic pulse recognition, infrared, andsurface acoustic wave technologies, among others. Some currenttouchscreens can discriminate among multiple, simultaneous touch pointsand/or are pressure-sensitive. Interaction with the touchscreen 110 istypically accomplished using fingers or thumbs, or for non-capacitivetype touch sensors, a stylus may also be used.

FIG. 2 shows an alternative landscape orientation for the electronicdevice 105 that may be utilized in some cases where the long axis of thedevice is substantially parallel to the plane of the ground. Theelectronic device here is arranged to switch the touchscreen to eitherlandscape mode or portrait mode (where the long axis is substantiallyorthogonal to the plane of the ground) either via user selection orautomatically, for example, through use of an accelerometer or otherdevice that can sense the orientation of the electronic device 105 whenheld by the user 102. FIG. 2 also depicts the electronic devicedisplaying a virtual keyboard 206 on the touchscreen 110. The virtualkeyboard 206 includes a plurality of icons that represent keycaps of aconventional keyboard, as shown. Touchscreen 110 will typically provideother functionalities such as a display area or editing window (notshown in FIG. 2) which shows the characters (i.e., letters, numbers,symbols) being typed by the user on the virtual keyboard 206.

FIG. 3 shows an alternative form-factor for an electronic device 305that can be used to support the calculator application. Electronicdevice 305 uses physical controls 307 (e.g., buttons, keyboard, and thelike) to replace or supplement the user interface that may be providedby a touchscreen 310. FIG. 4 shows another alternative form-factor foran electronic device 405 that can be used to support the calculatorapplication. Such device is often referred to as a “flip” or “clamshell”design which typically utilizes physical controls 407 in combinationwith a touchscreen or a non-touch-sensitive display 410. “Slider” typeelectronic devices, among other types, are also contemplated as beingusable for supporting the calculator application in some cases.

FIG. 5 shows that the touchscreen 110 can support user interactionthrough displayed icons (representatively indicated by reference numeral510) to facilitate user control, input, or navigation. In some cases,physical controls such as buttons, switches, and the like (representedby button 512) may be used to supplement or replace the icons 510displayed on the touchscreen 110. The icons 510 may represent contentsuch as files, documents, pictures, music, etc., that is stored orotherwise available (e.g., through a network or other connection) on thedevice 105. In this illustrative example, the icons represent variousapplications that are installed on the electronic device 105 that theuser may access. The calculator application is represented by icon 515.

The calculator application is typically implemented using device- ormachine-executable code that may be arranged in an application layer asshown in the software architecture 600 depicted in FIG. 6 which isoperable on the electronic device 105. Thus, the application layer willgenerally include one or more applications 607 each of which willtypically be represented by an icon 510 (FIG. 5) that is displayed onthe touchscreen 110. The applications 607 interact with the operatingsystem 613 which provides various methods, and functions required forthe applications to provide their intended functionality. The operatingsystem 613 also implements interfaces to various functional componentsthat are abstracted in a hardware layer 618 using, for example,respective device drivers 625.

FIG. 7 is a schematic view 700 of functional components that may beincluded in the electronic device 105. Control circuitry 707 may includeany processing circuitry or processor operative to control theoperations and performance of the electronic device 105. For example,control circuitry 707 can be used to run the operating system 613,firmware that is operable on the electronic device 105, media playback,media editing, or other capabilities, features, and applications. Insome implementations, the control circuitry 707 can drive a display andprocess inputs received from a user interface.

Storage 713 can include, for example, one or more storage mediaincluding a hard-drive, solid state drive, flash memory, permanentmemory such as ROM (read-only memory), any other suitable type ofstorage component, or any combination thereof. Storage 713 can store,for example, media data (e.g., music and video files), application data(e.g., for implementing functions on electronic device 105), firmware,user preference information data (e.g., media playback preferences),authentication information (e.g. libraries of data associated withauthorized users), lifestyle information data (e.g., food preferences),exercise information data (e.g., information obtained by exercisemonitoring equipment), transaction information data (e.g., informationsuch as credit card information), wireless connection information data(e.g., information that can enable electronic device 105 to establish awireless connection), subscription information data (e.g., informationthat keeps track of podcasts or television shows or other media a usersubscribes to), contact information data (e.g., telephone numbers ande-mail addresses), calendar information data, and any other suitabledata, or any combination thereof.

Memory 715 can include cache memory, semi-permanent memory such as RAM(random access memory), and/or one or more different types of memoryused for temporarily storing data. In some implementations, memory 715can also be used for storing data used to operate electronic deviceapplications, or any other type of data that can be stored in storage713. In some implementations, memory 715 and storage 713 can be combinedas a single storage medium.

I/O (input/output) circuitry 718 can be operative to convert (andencode/decode, if necessary) analog signals and other signals intodigital data. In some implementations, I/O circuitry 718 can alsoconvert digital data into any other type of signal, and vice-versa. Forexample, I/O circuitry 718 can receive and convert physical contactinputs (e.g., from a multi-touchscreen), physical movements (e.g., froma mouse or sensor), analog audio signals (e.g., from a microphone), orany other input. The digital data can be provided to and received fromcontrol circuitry 707, storage 713, memory 715, or any other componentof electronic device 105. Although I/O circuitry 718 is illustrated inFIG. 7 as a single component of the electronic device 105, severalinstances of I/O circuitry 718 can be included in electronic device 105in some implementations.

Electronic device 105 can include any suitable interface or componentfor allowing a user to provide inputs to I/O circuitry 718. For example,the electronic device 105 can include any suitable input mechanism, suchas for example, a button, keypad, dial, a click wheel, or a touchscreen.In some implementations, the electronic device 105 can include acapacitive sensing mechanism, or a multi-touch capacitive sensingmechanism.

In some implementations, the electronic device 105 can includespecialized output circuitry associated with output devices such as, forexample, one or more audio outputs. The audio output can include one ormore speakers (e.g., mono or stereo speakers) built into electronicdevice 105, or an audio component that is remotely coupled to electronicdevice 105 (e.g., a headset, headphones, or earbuds that can be coupledto a communications device with a wire or wirelessly).

In some implementations, I/O circuitry 718 can include display circuitry(e.g., a screen or projection system) for providing a display visible tothe user. For example, the display circuitry can include a screen (e.g.,an LCD screen) that is incorporated in electronics device 105. Asanother example, the display circuitry can include a movable display ora projecting system for providing a display of content on a surfaceremote from electronic device 105 (e.g., a video projector). In someimplementations, the display circuitry can include a coder/decoder(codec) to convert digital media data into analog signals. For example,the display circuitry (or other appropriate circuitry within theelectronic device 105) can include video codecs, audio codecs, or anyother suitable type of codec.

The display circuitry also can include display driver circuitry,circuitry for driving display drivers, or both. The display circuitrycan be operative to display content (e.g., media playback information,application screens for applications implemented on the electronicdevice, information regarding ongoing communications operations,information regarding incoming communications requests, or deviceoperation screens) under the direction of control circuitry 102.Alternatively, the display circuitry can be operative to provideinstructions to a remote display.

Communications circuitry 110 can include any suitable communicationscircuitry operative to connect to a communications network and totransmit communications (e.g., voice or data) from electronic device 105to other devices within the communications network. Communicationscircuitry 110 can be operative to interface with the communicationsnetwork using any suitable communications protocol such as, for example,Wi-Fi (e.g., an IEEE 802.11 protocol), Bluetooth™, radio frequencysystems (e.g., 900 MHz, 1.4 GHz, and 5.6 GHz communication systems),infrared, GSM (Global System for Mobile communications), GSM plus EDGE(Enhanced Data rates for Global Evolution), CDMA (Code Division MultipleAccess), quadband and other cellular protocols, VoIP (Voice overInternet Protocol), or any other suitable protocol.

In some implementations, communications circuitry 719 can be operativeto create a communications network using any suitable communicationsprotocol. For example, communications circuitry 719 can create ashort-range communications network using a short-range communicationsprotocol to connect to other devices. For example, communicationscircuitry 719 can be operative to create a local communications networkusing the Bluetooth protocol to couple electronic device 105 with aBluetooth headset.

Electronic device 105 can include one more instances of communicationscircuitry 719 for simultaneously performing several communicationsoperations using different communications networks, although only one isshown in FIG. 1 for sake of clarity in the drawing. For example,electronic device 105 can include a first instance of communicationscircuitry 719 for communicating over a cellular network, and a secondinstance of communications circuitry 719 for communicating over Wi-Fi orusing Bluetooth. In some implementations, the same instance ofcommunications circuitry 719 can be operative to provide forcommunications over several communications networks.

As shown in FIG. 8, in some implementations, the electronic device 105can be connected to a host device 807 such as a laptop or desktop PC fordata transfers, synching the communications device, software or firmwareupdates, providing performance information to a remote source or server,or performing any other suitable operation that may necessitate theelectronic device 105 being connected to the host device 807. A wiredconnection 812 such as one implemented using the USB (Universal SerialBus) protocol may be utilized, although wireless connections (not shownin FIG. 8), such as Bluetooth, between the electronic device 105 and thehost device 807 are alternatives in some implementations.

Such connection to the host device 807 may also facilitate access to aremote service and/or content provider 818 over the Internet 825. Forexample, electronic device 105 can access the service/content provider818 to download, for example, media content (e.g., music, videos,multimedia, etc.) and applications via the host device 807 (which iscoupled to the Internet 825 using a network gateway such as a modem829). Alternatively in some cases, the electronic device 105 may connectdirectly to the Internet 825 via a Wi-Fi connection 832 to the modem 829when the modem is configured with Wi-Fi functionality.

Several electronic devices 105 can also be coupled to a single hostdevice 807 using the host device as a server. Alternatively oradditionally, the electronic device 105 can be coupled to several hostdevices (e.g., to each of the plurality of the host devices to serve asa backup for data stored in electronic device 105).

FIG. 9 shows the user 102 launching the calculator application byactuating (i.e., touching) its icon 515 on the touchscreen on theelectronic device 105. Upon launch, a main calculator window 1003 isdisplayed on the touchscreen 110 as shown in FIG. 10. The maincalculator window 1003 includes a display area 1006 to showcalculations. The window also includes a variety of icons (collectivelyidentified by reference numeral 1012) that represent a numerical keypad,decimal key, backspace key, and mathematic operators (i.e., “+”, “−”,“×”, “÷” and “=”) that operate in a conventional manner. Severalspecialized keys are also included in the icon set 1012 including afunction key 1016, memory key 1021, display key 1025, and colon key 1029which are described in more detail below.

When the user 102 actuates the function key 1016, a function panelwindow 1103, as depicted in FIG. 11, is shown on the touchscreen display110. The function panel window 1103 includes the display area 1006 toshow the same calculations that are shown in the main calculator window1003 (FIG. 10). The function panel window 1103 also includes a varietyof icons (collectively identified by reference numeral 1112) thatrepresent various conventional mathematical functions and operators,such as parentheses for specifying the order of operations, square andsquare root, sign change (i.e., “+” to “−” and vice versa), andreciprocal. Several specialized keys are also included in the icon set1112 including a function key 1116 (which when actuated returns the user102 to the main calculator window 1003), preferences key 1121, memorykey 1125 (which functions similarly to the memory key 1021 shown in FIG.10), e-mail key 1130, time unit keys 1133, an insert key 1140, and adelete key 1145. Each of these specialized keys is described in moredetail below.

When the user 102 actuates the preferences key 1121, a preferenceswindow 1203 is shown on the touchscreen display 110. The preferenceswindow 1203 includes various user-selectable options for setting andselecting certain user preferences as to how the calculator applicationoperates. For example, the user 102 can touch a switch icon 1207 to setwhether an audible key click is emitted by the electronic device 105when keys are actuated. Similarly, switches 1210, 1213, 1215, and 1218may be set by the user 102 to enable or disable particular features asrespectively shown in FIG. 12. Thus, turning switch 1210 to the “on”position allows a subtotal to be calculated when a line in the displayarea 1006 is tapped.

If switch 1213 is “on”, then the memories (as described below) may beerased. If switch 1215 is “on”, then a warning dialog is displayed tothe user 102 prior to memories being erased. If switch 1218 is “on”,then a warning dialog is displayed to the user 102 when the colon key1029 (FIG. 10) is actuated to confirm that the user intends to entervalues using a time format. Icon 1221 enables the user 102 to select apreference for the time format that is displayed by the calculatorapplication (as described in more detail below). Icon 1225 enables theuser 102 to select a preference for certain memory functionality (asdescribed in more detail below). Icon 1230 enables the user 102 toselect a preference for default memory names (as described in moredetail below). When button 1233 is actuated, the user 102 is returned tothe main calculator window 1003 (FIG. 10).

When the arrow button 1238 is actuated, a decimal precision window 1303is shown on the touchscreen display 110. By interacting with thiswindow, the user 102 may select the number of decimal places that aredisplayed by the calculator application 515. The user 102 may interactwith a slider 1310 to select the desired decimal precision from zerodigits past the decimal point to up to six digits past the decimalpoint. Alternatively, the user 102 may choose from among several presetsfor decimal precision by actuating the appropriate buttons 1313, 1316,1321, and 1327 which respectively set the decimal point precisionautomatically to zero digits (i.e., none), to two digits to representhundredths in monetary calculations, or to the maximum value of sixdigits, as shown in FIG. 14. When the decimal precision is set to auto,the calculator application 515 will use as many decimal places asnecessary when displaying calculations. The user 102 may select whethertrailing zeroes are displayed by the calculator application 515 bytoggling switch 1330 to the desired “on” or “off” position. When button1335 is actuated, the user 102 is returned to the preferences window1203.

FIG. 15 illustrates how the calculator application 515 supports the useof a “virtual” tape 1505 for displaying calculations as well asorganizing calculator application memories. Use of a tape paradigm inthe calculator application 515 is intended to replicate the positiveuser experience that is typically encountered when interacting with aconventional adding machine or printing calculator which utilizes aphysical paper tape (as respectively indicated by reference numerals1512 and 1515). More particularly, a paper tape readily allows a user tosee a chain of calculations and ensure that all of the values andoperators were correctly entered. Such a visual confirmation can beespecially helpful, for example, when a chain of calculations is longand/or complex. It is noted that from this point on in the descriptionthat use of the term “tape” means a virtual tape that is supported bythe calculator application in accordance with the principles describedherein, unless otherwise specified.

The virtual tape 1505 provides all the benefits of visual confirmationof values and operators in a given calculation while adding additionalfeatures and functionalities that are difficult or impractical toimplement using a conventional paper tape, as described in more detailbelow. As shown in FIG. 15, the virtual tape 1505 may be visualized asscrolling along the electronic device 105 where a portion of the tape isvisible in the display area 1006 at a given instance in time. That is,as the user 102 enters values and operators when performing acalculation, the values and operators are shown in the display area 1006as if they were printed onto the virtual tape 1505. As more values andoperators are entered, the virtual tape 1505 will scroll upwards toenable the latest values and operators to be viewed by the user 102 inthe display area 1006 as they are entered.

As shown in FIGS. 16 and 17, the calculator application 515 isconfigured to enable the user 102 to readily view any portion of thevirtual tape 1505 by touching a portion of the display area and thendragging the display either upwards or downwards to see the desired tapeportion. In this illustrative example, the calculator application 515may implement gesture-sensitive scrolling so that, for example, the user102 can use a fast flick of a digit (i.e., finger or thumb) so that thevirtual tape 1505 scrolls relatively quickly by, before eventuallyslowing down and stopping (or by being stopped by the touch of the user102 at the desired location). Alternatively, a slow drag of the digitacross the touchscreen can enable very fine control over the tape'sposition. Accordingly, as illustratively shown in FIGS. 16 and 17, theuser 102 can touch the touchscreen 110 and drag downwards to move thecalculation chain from a first position in the display area 1006 (asindicated by reference numeral 1602) to a second position (as indicatedby reference numeral 1702 in FIG. 17) to thereby reveal values andoperators that are positioned higher on the virtual tape 1505.

FIG. 18 illustrates another feature that is provided by the calculatorapplication 515, namely that multiple virtual tapes 1803 _(1, 2 . . . N)may be simultaneously supported as memories that can be accessed by theapplication. That is, memories and tapes are functionally equivalent sothat memories may be conceptually regarded as tapes, and tapes asmemories. Accordingly, in the description that follows, the terms “tape”and “memory” may be used interchangeably and have the same meaningunless context or an explicit statement is made which indicates thecontrary. The multiple tape support feature is shown in FIGS. 19-31 andthe accompanying text.

FIG. 19 depicts an illustrative memories window 1903 that is shown onthe touchscreen display 110 (FIG. 1) when the user 102 actuates thememory key from either the main calculator window 1003 shown in FIG. 10(key 1021) or from the function panel window 1103 shown in FIG. 11 (key1125). As shown in FIG. 19, there are five tapes listed in the memorieswindow 1903 which can be selected by the user 102. The listed tapes arenamed “Tape” (indicated by reference numeral 1910), “Business income”1915, “Household expenses” 1921, “Travel expenses” 1926, and“Investments” 1930. It is emphasized that these names and thecalculations contained therein are arbitrary and intended to beillustrative.

To the right of each of the tape names in the memories window 1903 isthe last value on each of respective tapes. Thus, “Tape” has a lastvalue of 2,215.12, “Business income” has a last entry of 6,203.08, andso forth. A mathematical total of all the tape's last values is alsoshown in the memories window 1903, as indicated by reference numeral1934. The presentation of the available tapes, the respective lastvalues contained therein, and the mathematical total of the last valuesin a single window can often be expected to be beneficial to many users.For example, unlike memory recall features that are implemented in manyconventional calculators, the user of the present calculator applicationcan see the values in memory prior to recalling, or otherwise using suchvalues.

When button 1940 is actuated, the user 102 is returned to the maincalculator window 1003 (FIG. 10). When button 1945 is actuated, a newtape is added to the list. In this example, a taped named “E” (asindicated by reference numeral 1949) has been added (it is noted thatmemory names start with letters by default according to the preferenceset by icon 1230 as described in the text accompanying FIG. 12 above).

Buttons 1955, 1958, and 1962 enable the user 102 to select therespective actions of recalling, displaying, or showing details aboutthe selected tape. As shown in FIG. 19, the “Display” button 1958 isselected. Accordingly, the “Household expenses” tape listing whenselected by the user 102, as shown in FIG. 20, will be displayed. FIG.21 shows the “Household expenses” tape 2112 in its entirety (recognizingthat only a portion of a tape is viewable at a time in the display area1006). As shown, the tape's name is displayed along the left edge of thetape, typically using a graphic device 2116 that mimics a watermark orother visible, but unobtrusive marking Similarly, FIGS. 22-24respectively show the “Business Income” tape 2212, “Travel Expenses”tape 2312, and “Investments” tape 2412. As noted above the last value oneach tape (as indicated with an arrow in each FIG) is what is shown onthe memories window 1903 (FIG. 19). Typically, the last value on a giventape will be the result of a calculation, but it does not necessarilyhave to be a calculated result.

FIG. 25 shows the “Detail” button 1962 as being selected. Accordingly,details regarding the “Household Expenses” tape when selected by theuser 102, as shown, will be displayed. Alternatively, details about anygiven tape may be displayed when the corresponding arrow button on a rowis selected (as representatively indicated by reference numeral 2505).

FIG. 26 shows a memory details window 2612 that shows details associatedwith an illustrative tape 2112 (FIG. 21). The name of the tape isdisplayed in an editable name field 2620. The user 102 may employ thefield 2620 to change the tape's name from its default value i.e., aletter or a number depending on the preference selected by the user asdiscussed above. In this example, the user 102 named the tape “HouseholdExpenses” as shown. The memory's value is indicated by reference numeral2626. An optional comment for the tape may be entered in editable field2630 and optional annotations may be entered in editable field 2640.

When the user 102 touches one of the editable fields (fields 2620, 2630,and 2640, as shown in FIG. 27, a virtual keyboard 2705 is displayed onthe touchscreen which enables the user to enter a desired string ofcharacters into a respective field. In this illustrative example, theuser 102 is entering the string “May 2010” into the comment field 2630,as indicated by the cursor 2712 which typically is configured to blink.A button 2718 is also provided which clears the field 2630 when actuatedby the user 102.

As shown in FIG. 28, the comment “May 2010” that is entered in thecomment field 2630 (FIG. 27) is displayed on the tape 2112, as indicatedby reference numeral 2802. While the comment 2630 is located towards thetop of the tape 2112 in this example, other locations on the tape mayalso be used to display the comment depending on the requirements of aparticular implementation of the calculator application. As shown inFIG. 29, the annotation “Utilities” that is entered in the annotationfield 2640 (FIG. 27) is displayed on the tape 2112, as indicated by thereference numeral 2902 above the first numerical value (i.e., −89.25) atthe top of the tape 2112. In some implementations, the annotationfeature may operate so that the user 102 can go to memory details window2612 and use the annotation field 2640 to place an annotation at thecurrent position in any given tape. This capability would enable, forexample, use of multi-line annotations (as indicated by referencenumeral 2913) as well as line-by-line annotations (i.e., a separateannotation for one or more of the values entered on a tape), asindicated by reference numeral 2920. Alternatively, a separateannotation window could be used (and accessed by the user 102 via anappropriate button on the function panel 1103 shown in FIG. 11 anddescribed in the accompanying text, for example) to generate single ormulti-line annotations as may be required to meet the needs of aparticular calculator application implementation. It is further notedthat annotations can be positioned at different and varying locations ona tape by implementation. Thus, for example, in some implementations theannotation may precede a value on the tape, while in otherimplementations it may be placed next to a value, or following the value(or combinations of placement positions may be utilized).

Returning to FIG. 26, the memory details window 2612 includes a displaybutton 2648, delete button 2652, e-mail button 2656, and recall button2660. If the user actuates the display button 2648, the tape associatedwith the memory details window (in this example, the Household Expensestape 2112) will be displayed so that it can be reviewed or edited. Whenthe delete button 2652 is actuated, the tape associated with memorydetails window 2612 will be cleared (i.e., erased). If the warningswitch 1215 is set to “on” (as shown in FIG. 12 and described in theaccompany text), a dialog box will be displayed to the user 102 toconfirm that the user wants to erase the tape prior to actually clearingit.

When the e-mail button 2656 is actuated, the tape associated with thememory details window 2612 will be placed into a queue for e-mailing.The e-mail queue may be viewed by actuating the e-mail button 1130 inthe function panel window 1103 (FIG. 11). As shown in FIG. 30, an e-mailwindow 3003 is then displayed on the touchscreen display. The e-mailwindow 3003 provides commonly utilized editable “To:” and “Cc/Bcc:” textentry lines, respectively indicated by reference numerals 3010 and 3015,as well as a default subject in the “Subject:” line 3018. In someimplementations, the user 102 may be provided with a facility to pickfrom among e-mail contacts that are stored in a contacts list or mailapplication that may be running on the electronic device that hosts thecalculator application. Typically, such contacts or e-mail applicationsexpose APIs (application programming interfaces) or other facilities toenable such functionality to be implemented by other applications.

The calculator application automatically populates the body of thee-mail 3025 with the values and operators as they appear on the tape (inthis example, the Household Expenses tape 2112). Line numbers are alsoincluded in the e-mail 3025 to indicate the positions of the values onthe tape. The user 102 can send the e-mail or cancel it using therespective send button 3030 or cancel button 3032. If the e-mail issent, then the calculator application will generally interface with amail application that is operable on the electronic device and hand offthe e-mail to the mail application for delivery using itsfunctionalities.

Returning again to FIG. 26, the recall button 2660 operates to recallthe last value on a tape as a memory which can be placed at the currentposition on another tape. The memory recall function may also be invokedby the user 102 using button 1955 in the memories window 1903, as shownin FIG. 31, to specify the recall action when a tape is selected. Inthis illustrative example, the user 102 has selected the Investmentstape 1930, as indicated by the highlighting, which has a memory value of2,218.56 (i.e., the last value on that tape). As shown in FIG. 32, theuser 102 is performing a chain of calculations on the tape 1505 (FIG.15) and has entered the “+” operator 3202 at the current line 3206. Theuser 102 may recall the Investments tape value as a memory using therecall button 1955 from the memories window 1903 as shown in FIG. 31 (orthe recall button 2660 from the memory details window 2612 shown in FIG.26). When recalled, the calculator application inserts the memory valuefrom the Investment tape into the current position on the tape 1505, asshown in FIG. 33 as indicated by reference numeral 3306. A textreference may also be included (“Investments Rcl” in this example) toindicate the source of the recalled memory on the tape 1505. Afterrecalling a value, the user 102 is free to make additional entries orperform other calculations. In this example, the user has entered the“=” operator to arrive at the last value of “4,433.68” on the tape.

Another feature of the calculator application is to provide thecapability to edit entries on any of the tapes 1803 (FIG. 18). Forexample, as shown in FIG. 34 the user 102 may edit a tape by touching anentry 3411 (in this example, a value on the Investments tape 2412) tohighlight it. When highlighted, the user 102 can use the backspace key3508 shown in FIG. 35 to delete digits in the entry and then use thekeypad 1012 to key in the new digits. The calculator application updatesall the calculations on the fly as the user 102 makes each edit. Suchfeature is termed here as “live edits.” In this illustrative example, asshown in FIG. 35, the user 102 has deleted the two digits after thedecimal point in the entry 3511 which is reflected in the new calculatedtotal (as indicated by reference numeral 3516).

As shown in FIG. 36, the user 102 has edited the entry so that it is nowshown on the Investments tape as “144.36” (as indicated by referencenumeral 3612). The calculator application calculates the new total as“2,248.56” (as indicated by reference numeral 3620). In addition, thecalculator application will recalculate any tape that is affected by theuser's edit. For example, as tape 1505 uses the Investments tape 2412 asa memory, the calculator application will show the new Investments tapetotal in the appropriate location on the tape 1505, as indicated byreference numeral 3625 and recalculates a new total “4,463.68” (asindicated by reference numeral 3632).

In addition to supporting live edits of values, the calculatorapplication enables the user to edit operators as well. For example, asshown in FIG. 37, the operator on a tape 3705 reflects a user's editfrom “+” to “×” (as respectively indicated by reference numerals 3712and 3715). The calculator application recalculates the tape (and anytape that uses the user-edited tape as a memory) and displays the newvalues resulting from the edited operator, which in this example is anew total, as indicated by reference numeral 3722.

As noted above in the text accompanying FIGS. 11 and 12, the calculatorapplication supports entry of values and calculations using units oftime through use of the colon key 1029 (FIG. 10). For example as shownin FIG. 38 the first value (indicated by reference numeral 3806) on tape3803 is entered as “2:33” which, according to the user preference fortime units set in the preferences window 1203 (FIG. 12), means two hoursand thirty-three minutes. A time indicator “h” (indicated by referencenumeral 3810) is displayed on the tape 3803 to affirmatively visuallyconfirm the time units. FIG. 38 further shows that a second time valueof “1:31” (one hour and thirty one minutes) is being added to the firstand that the total (indicated by reference numeral 3814) properly showsthe sum as being “4:04” (four hours and four minutes).

The calculator application enables values to be converted from one timeunit to another (e.g., hours, minutes, seconds, days, months, years)using time unit keys 1133 in the function panel window shown in FIG. 11.Accordingly, as shown in FIG. 38, the user 102 has converted the sum offour hours and four minutes to corresponding values using various othertime units, as indicated by reference numeral 3820. Time indicators(e.g., “m”, “D”, “s” for minutes, days, and seconds) are displayed nextto the values on the tape 3803 to provide a confirmation of the timeunits being used.

The user's selected preference for time in the time preferences window1203 (FIG. 12) enables the calculator application to interpret raw(i.e., unitless) values according to the selected preference whenperforming time-based calculations. For example, as shown in FIG. 39,the calculator application will interpret the “2” in the firstcalculation 3903 on the tape 3910 to be in units of hours if the timepreference is set for hours and minutes. Accordingly, the calculationcomprises the addition of two hours to the value of three hours andfifteen minutes to result in the sum of five hours and fifteen minutes.By contrast, if the user sets the time preference for minutes andseconds in the preferences window 1203, then the calculator applicationwill interpret the “2” to be in units of minutes. This is shown in thesecond calculation 3917 on the tape 3910 where the calculation comprisesthe addition of two minutes to the value of three hours and fifteenminutes to result in the sum of three hours and seventeen minutes.

In addition to being added, time values can be subtracted and multipliedor divided by non-time values as respectively shown in calculations3925, 3931, and 3949 on the tape 3910. Tape 3910 further depicts howmultiple calculations (both time-based and non-time-based) may besupported on a single tape. As noted above, the last value on the tapeis used as the tape's memory value, which in this example is “45.00” asindicated by reference numeral 3955.

FIG. 40 highlights other features supported by the calculatorapplication. In particular, parentheses are displayed using variousindents to indicate the level of nesting within a given calculation. Thecalculation 4005 shown on tape 4011 is 2+((2.3+6.2)÷6)=3.42 whichincludes two parenthetical expressions with one nested within the other.The calculator application evaluates the inner parenthetical expressionby adding the values 2.3 and 6.2 which results in 8.50. Thisintermediate result (8.50) is displayed by the calculator application onthe tape 4011 as indicated by reference numeral 4025. The outerparenthetical expression is then evaluated by dividing the result of theinner parenthetical expression by 6. This result (1.42) is displayed bythe calculator application on the tape 4011, as indicated by referencenumeral 4031, to which 2 is added to result in a calculated value of3.42. Both the indenting feature for nested parenthetical expressionsand the display of the intermediate results of the evaluation of theexpressions is expected to make using and keeping track of parentheticalexpressions easier for the user. Parentheses may also be live edited (ina similar manner as with values and operators) as an additional featurethat is supported by the calculator application.

FIG. 41 depicts an illustrative display window 4112 that may bedisplayed as part of the user interface supported by the main calculatorwindow 1003 in the calculator application. The display window 4112 istoggled on and off (i.e., shown and hidden) using the display key 1025.The display window 4112 is configured to function in a similar manner toa conventional single-line calculator display by showing only thecurrent line such as a value the user enters with the keypad or a resultthat is calculated by the calculator application. Some users may preferto see and use a more traditional display in some cases, but the displaywindow 4112 can always be hidden if more room is needed to see and workwith the tape.

As shown in FIG. 41, the window 4112 displays a number “4.85” (indicatedby reference numeral 4115) which matches the current line in the tape(indicated by reference numeral 4121). A unit indicator 4127 is alsoshown in the display window 4112 to indicate if a displayed number is aregular decimal number or if it represents units of time (and if in timeunits, whether such units are hours, minutes, or seconds). In thisexample, the indicator “Dec” is highlighted in the unit indicator 4127to show that the displayed number is a regular decimal number.

The display window 4112 supports a feature that enables the user 102 toselect the number of digits displayed past the decimal by touching thedisplay window 4112 and dragging to the right or left. As shown in FIG.42, if the user 102 touches the display window 4112 and then drags tothe right, the displayed number changes from “4.85” to “4.9.” That is,the decimal precision of the displayed number 4115 is changed from twodigits to a single digit and the displayed value is rounded up or downas appropriate. As shown in FIG. 43, as the user 102 continues to touchand drag to the right, the displayed number 4115 will show only digitsto the left of the decimal. In this example, the displayed numberchanges from “4.9” to “5.” If the user 102 touches the display windowand drags to the left, then additional digits past the decimal pointwill be displayed. As shown in FIG. 44, the user 102 has revealed fourdigits to the right of the decimal point. If the user 102 continues totouch and drag to left, up to six digits past the decimal point may bedisplayed in this illustrative implementation of the calculatorapplication.

The unit indicator 4127 in the display window 4112 may be utilized totoggle the displayed number between decimal and time units. As shown inFIG. 45, by touching “Hours” in the unit indicator 4127, the displayednumber will change to reflect hours and minutes (i.e., 4.85 hours isequivalent to four hours and 51 minutes). By touching other unitindicators, additional conversions may be performed. For example, asshown in FIG. 46, by touching “Minutes” in the unit indicator 4127, thedisplayed number will change to reflect minutes. In this example, fourhours and fifty one minutes is equivalent to 291 minutes.

Although the subject matter has been described in language specific tostructural features and/or methodological acts, it is to be understoodthat the subject matter defined in the appended claims is notnecessarily limited to the specific features or acts described above.Rather, the specific features and acts described above are disclosed asexample forms of implementing the claims.

1. One or more non-transitory computer-readable media storinginstructions which, when executed on an electronic device, implement acalculator application configured for performing a method comprising thesteps of: receiving a sequence of values and operators which comprise acalculation that are entered by a user on a keypad implemented by thecalculator application via a user interface; implementing a virtual tapefor storing the sequence and being displayed on the user interface toshow at least portions of the stored sequence responsively to userselection, the displayed virtual tape being arranged as auser-accessible memory so that user-selected data or a user-selectedcalculated result in the displayed virtual tape is linkable to one ormore respective virtual tapes in a plurality of virtual tapes, thelinking comprising enabling the user-selected data or user-selectedcalculated result to be shown on a linked virtual tape when displayed orused by a calculation on a linked virtual tape, each of the virtualtapes i) being alternatively displayed one at a time via the userinterface responsively to user selection, and ii) including a visiblegraphic device, the visible graphic device resembling a watermark andproviding information to uniquely identify a given virtual tape whendisplayed on the user interface; configuring the user interface toenable live editing of the values or the operators in the storedsequence on the displayed virtual tape; responsively to the liveediting, dynamically updating the calculation on the virtual tape anddynamically updating the calculations on any linked virtual tape; andshowing the updated calculation on the displayed virtual tape.
 2. Theone or more non-transitory computer-readable media of claim 1 includinga further step of arranging each of the plurality of virtual tapes tostore a sequence of values and operators for a respective plurality ofcalculations, the sequence of values and operators for the respectiveplurality of calculations being received via user input on the keypad.3. The one or more non-transitory computer-readable media of claim 1including a further step of utilizing each of the plurality of virtualtapes as a user-accessible memory, the user-accessible memory beingrecallable by the user through the user interface for inclusion as arecalled value in calculations on any of the plurality of virtual tapes.4. The one or more non-transitory computer-readable media of claim 1including an additional step of configuring the user interface foraccepting one of textual comment or annotation from the user, thetextual comment or annotation being shown on the virtual tape.
 5. Theone or more non-transitory computer-readable media of claim 4 in whichthe user interface is configured so that annotations may be associatedon a line-by-line basis with values.
 6. An electronic device,comprising: storage adapted for storing instructions that when executedduring runtime on the electronic device implement a calculatorapplication using a plurality of virtual tapes, each of the virtualtapes being used by the calculator application to store and displaycalculations comprising a sequence of values and operators entered by auser through a user interface exposed by the calculator application;control circuitry adapted for configuring the plurality of virtual tapesas a plurality of respective user-accessible memories that are eachlinkable, under control of a user through the user interface, to one ormore virtual tapes in the plurality of virtual tapes, each of thevirtual tapes i) being configured so that the stored sequence isviewable by the user on the user interface according to user selection,and ii) including a visible graphic device, the visible graphic deviceresembling a watermark and providing information to uniquely identify agiven virtual tape, each of the user-accessible memories beingconfigured for storing user-selected data or a user-selected calculatedresult as a memory value that is includable as a recalled value in theone or more linked virtual tapes, the selecting of the one or morevirtual tapes being performed through the user interface; andinput/output circuitry adapted for receiving input from a user throughthe user interface implemented by the calculator application duringruntime and, responsively to a selection by the user, displaying the oneor more linked virtual tapes one at a time, the displaying includingshowing the unique identifying watermark and the recalled value, andwherein the control circuitry is further adapted for dynamicallyupdating the recalled value in the one or more linked virtual tapeswhenever the memory value changes.
 7. The electronic device of claim 6in which the input/output circuitry is further adapted for exposing alive editing functionality to the user through the user interface sothat values or operators in the calculations are selectively changedthrough editing by the user and recalculating the memory valueresponsively to the editing.
 8. The electronic device of claim 7 inwhich the user interface includes a touchscreen and in which theinput/output circuitry is further adapted for enabling the user toscroll through the selected virtual tape using the touchscreen.
 9. Theelectronic device of claim 6 in which the memory value is the last valueon a virtual tape.
 10. The electronic device of claim 6 in which theinput/output circuitry is further adapted for exposing functionalitythrough the user interface to input a name for one or more of thevirtual tapes in the plurality.